Silhouette-Opaque Transparency Rendering

Keywords

Abstract

Transparency in 3D graphics has traditionally been created
by ordering the transparent objects from back-to-front with
respect to the viewpoint, and rendering the opaque objects
first and then the transparent objects in the prescribed or
der. This has three major disadvantages: need for splitting
intersecting polygons, repeated ordering for varying view
points, and finally, incorrect transparency at the regions
near silhouettes. The first two problems are eliminated by
order independent transparency rendering techniques. The
goal of this paper is to eliminate the third disadvantage also.
Silhouettes look more opaque than the rest of the regions
of the model. We call this silhouette-opaque transparency
rendering. We use the alpha value as a probabilistic mea
sure, similar to other order independent methods. We dif
fer from the traditional methods by using this probabilis
tic measure in object space rather than in image space to
render the transparency in silhouettes correctly. We call
our technique to achieve silhouette-opacity as object-space
screen-door transparency.